As is disclosed in Non-patent literature 1 (p. 136-p. 137), development of neural networks is regulated mainly by action of an attractive axon guidance factor and a repulsive axon guidance factor on a growth cone which is located at the tip of a neurite. The attractive axon guidance factor causes the neurite to grow in a predetermined direction, and the repulsive axon guidance factor causes growth cone collapse, thereby reducing neurite elongation.
Clarification of a detailed mechanism of regulation of development of neural networks would lead to induction of appropriate development of neural networks and induction of regeneration of neural networks. However, many unclear points still remain even in a mechanism of induction of growth cone collapse caused by a repulsive axon guidance factor.